| Message ID | 20240610181046.1991436-5-linux@roeck-us.net (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
| Series | hwmon: Update handling of chip-id enums | expand |
On Mon, 2024-06-10 at 11:10 -0700, Guenter Roeck wrote: > If a driver calls device_get_match_data(), the .data pointer in its id > data structures must not be NULL/0 because device_get_match_data() > returns NULL if an entry is not found. Explain that in a comment to avoid > confusion why this is required in this driver but not in other drivers. > > Cc: Daniel Matyas <daniel.matyas@analog.com> > Signed-off-by: Guenter Roeck <linux@roeck-us.net> > --- Acked-by: Nuno Sa <nuno.sa@analog.com> > drivers/hwmon/max31827.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/drivers/hwmon/max31827.c b/drivers/hwmon/max31827.c > index f8a13b30f100..391cb059e94d 100644 > --- a/drivers/hwmon/max31827.c > +++ b/drivers/hwmon/max31827.c > @@ -46,6 +46,11 @@ > #define MAX31827_M_DGR_TO_16_BIT(x) (((x) << 4) / 1000) > #define MAX31827_DEVICE_ENABLE(x) ((x) ? 0xA : 0x0) > > +/* > + * The enum passed in the .data pointer of struct of_device_id must > + * start with a value != 0 since that is a requirement for using > + * device_get_match_data(). > + */ > enum chips { max31827 = 1, max31828, max31829 }; > > enum max31827_cnv {
diff --git a/drivers/hwmon/max31827.c b/drivers/hwmon/max31827.c index f8a13b30f100..391cb059e94d 100644 --- a/drivers/hwmon/max31827.c +++ b/drivers/hwmon/max31827.c @@ -46,6 +46,11 @@ #define MAX31827_M_DGR_TO_16_BIT(x) (((x) << 4) / 1000) #define MAX31827_DEVICE_ENABLE(x) ((x) ? 0xA : 0x0) +/* + * The enum passed in the .data pointer of struct of_device_id must + * start with a value != 0 since that is a requirement for using + * device_get_match_data(). + */ enum chips { max31827 = 1, max31828, max31829 }; enum max31827_cnv {
If a driver calls device_get_match_data(), the .data pointer in its id data structures must not be NULL/0 because device_get_match_data() returns NULL if an entry is not found. Explain that in a comment to avoid confusion why this is required in this driver but not in other drivers. Cc: Daniel Matyas <daniel.matyas@analog.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net> --- drivers/hwmon/max31827.c | 5 +++++ 1 file changed, 5 insertions(+)